Abstract

Aim: to define comparative values of pH, iron, calcium and magnesium in exhaled breath condensate (EBC) of children with acute asthma exacerbation, children with gastoesophageal reflux disease (GERD) and controls. ----- Subjects:exhaled breath condensate (EBC) was collected with standard method by using an EcoScreen condenser (Erich Jaeger GmbH, Hoechberg, Germany). Each sample was submitted to argon overlining (6 Lmin-1 for 2 minutes). Right afterwards the determination of pH, pO2 and pCO2 on the Ecosys II analyzer (EschWeilerGmbH &Co. KG, Kiel, Germany) proceded. Then the EBC sample was stored at –80°C. After derfosing, the concentrations of iron, calcium and magnesium were determined on an automated selective Olympus AU 400 analyzer (Olympus, Tokyo, Japan). ----- Results: reduced values of pH in EBC of asthmatic children comparing to controls doubtlesly showed the existance of acid stress in fluid that overlines the airways, which was not the case in children with GERD. Disturbed homeostasis in lungs was proven both at patients with acute asthma exacerbation and GERD, which points out the dynamic changes between oxidative and antioxidative processes inside the respiratory system within these two groups. The altered relation between magnesium and calcium of both patients with acute asthma exacerbation and patients with GERD comparing to controls points at redistribution of these ions between the bronchii smooth muscle cells and the fluid that overlines them. ----- Conclusion: diagnostic value was found at determining pH in children with acute asthma exacerbation, then iron and magnesium/calcium ratio both in children with acute asthma exacerbation and GERD. Very important role in the pathophisiology of asthma and GERD plays the inflammation (acid stress), the disturbed homeostasis of iron (oxidative stress), and the redistribution of calcium and magnesium (bronchoconstriction). Chosen biomarkers from the EBC can complete the results of FENO and lung function measuring in children with asthma and the results of 24-hour pH-measurement in children with GERD.